New research from Oregon State University (OSU) suggests that laws allowing cyclists to treat stop signs as yield signs do not lead to unsafe behavior by either bicyclists or motorists. This finding could have significant implications for urban planning and traffic laws across the United States.
The study, published in Transportation Research Part C, used an innovative experimental technique that linked separate bicycle and motor vehicle simulators. This allowed researchers to observe how cyclists and drivers interact at intersections under various conditions.
Understanding Rolling-Stop Laws
Rolling-stop laws, also known as “Idaho stop” laws after the state that first implemented them in 1982, allow cyclists to treat static stop signs as yield signs. The primary argument for these laws is that they allow riders to maintain momentum, potentially reducing intersection congestion and crash risk by helping cyclists clear intersections faster.
David Hurwitz, a transportation engineering professor at OSU and the study’s leader, explains: “We evaluated safety-relevant behaviors associated with laws stemming from the ‘Idaho stop,’ which was put on the books in 1982 but largely ignored around the country until not long ago.”
Since 2017, seven states have enacted bicycle rolling-stop laws, including Oregon in 2019 and Washington in 2020. Arkansas, Delaware, North Dakota, Oklahoma, and Utah have also implemented similar legislation, with several other states considering it.
Novel Research Approach
The OSU study stands out for its innovative methodology. “It required fully connecting two independent simulators, running subjects in pairs simultaneously and having each subject interacting with an avatar of the other in a shared virtual world,” Hurwitz said.
This approach allowed researchers to observe 60 participants in pairs as they navigated 16 “live-interaction” scenarios involving a bicyclist and motorist meeting at a four-way, stop-controlled intersection.
Key Findings and Implications
The study’s results challenge some common concerns about rolling-stop laws. After receiving education about the law, cyclists preferred to yield rather than stop completely and moved through intersections more quickly. Drivers, on the other hand, either approached intersections more slowly or at a similar speed after learning about the law.
These findings suggest that educating both cyclists and motorists about rolling-stop laws could lead to safer, more efficient interactions at intersections. This is particularly relevant given that nearly half of all bicycle-car crashes occur at intersections, according to Hurwitz.
The research also addresses concerns about aggressive behavior towards cyclists. Previous studies have indicated that drivers tend to be more aggressive toward cyclists when they believe riders are breaking the law. However, this study found no evidence of increased aggression after implementing rolling-stop laws.
Why It Matters
This research has significant implications for urban planning, traffic safety, and public policy. As more cities and states consider implementing bicycle-friendly laws to encourage sustainable transportation, understanding the impact of these laws on safety is crucial.
The findings are particularly relevant for regions with high numbers of bicycle commuters. Oregon and Washington, for example, have some of the largest percentages of bicycle commuters in the country. According to the League of American Bicyclists’ 2017 Report on American Community Survey, Portland has the second-largest number of bicycle commuters in the United States, with about 22,000 riders, while Seattle has approximately 17,000.
As Hurwitz notes, “The findings suggest more outreach in regard to rolling-stop laws would be useful, and this research gives decision-makers information to support prospective legislative policies, set up educational programs and design robust enforcement practices.”
With 1,105 bicyclists killed in collisions with motor vehicles in the United States in 2022 (a 13% increase from 2021), according to the National Highway Traffic Safety Administration, any measures that could potentially improve cyclist safety are worthy of serious consideration.
This study provides valuable evidence that could help shape future traffic laws and urban planning decisions, potentially leading to safer and more efficient transportation systems for all road users.
